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https://www.readbyqxmd.com/read/28107308/acute-right-heart-failure-after-hemorrhagic-shock-and-trauma-pneumonectomy-a-management-approach-a-blinded-randomized-controlled-animal-trial-using-inhaled-nitric-oxide
#1
Andrea L Lubitz, Lars O Sjoholm, Amy Goldberg, Abhijit Pathak, Thomas Santora, Thomas E Sharp, Markus Wallner, Remus M Berretta, Lauren A Poole, Jichuan Wu, Marla R Wolfson
BACKGROUND: Hemorrhagic shock and pneumonectomy causes an acute increase in pulmonary vascular resistance (PVR). The increase in PVR and right ventricular (RV) afterload leads to acute RV failure, thus reducing left ventricular (LV) preload and output. Inhaled nitric oxide (iNO) lowers PVR by relaxing pulmonary arterial smooth muscle without remarkable systemic vascular effects. We hypothesized that with hemorrhagic shock and pneumonectomy, iNO can be used to decrease PVR and mitigate right heart failure...
February 2017: Journal of Trauma and Acute Care Surgery
https://www.readbyqxmd.com/read/28100164/relation-between-arterial-stiffness-and-aerobic-capacity-importance-of-proximal-aortic-stiffness
#2
Tsubasa Tomoto, Seiji Maeda, Jun Sugawara
Brachial-ankle pulse wave velocity (baPWV) has become a popular modality of arterial stiffness measurement. However, its projected arterial segment does not include the proximal aorta which plays important roles for attenuating cardiac pulsation and reducing afterload. We hypothesised that aerobic capacity would be more strongly associated with PWV including the proximal aorta than that omitting the proximal aorta. To test our hypothesis, we compared the association between aerobic capacity and arterial stiffness parameters omitting vs...
January 19, 2017: European Journal of Sport Science
https://www.readbyqxmd.com/read/28099680/novel-putative-pharmacologic-therapies-to-protect-the-right-ventricle-in-pulmonary-hypertension-a-review-of-current-literature
#3
REVIEW
Gerald J Maarman, Rainer Schulz, Karen Sliwa, Ralph Schermuly, Sandrine Lecour
Pulmonary hypertension (PH) is defined by elevated mean pulmonary artery pressure following the pathologic remodelling of small pulmonary arteries. An increase in right ventricular (RV) afterload results in RV hypertrophy and RV failure. The pathophysiology of PH, and RV remodelling in particular, are not well understood, thus explaining, at least in part, why current PH therapies have a limited effect. Existing therapies mostly target the pulmonary circulation. Because the remodelled RV fails to support normal cardiac function, patients eventually succumb from RV failure...
January 18, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28098356/mechano-chemo-transduction-in-cardiac-myocytes
#4
Ye Chen-Izu, Leighton T Izu
The heart has the ability to adjust to changing mechanical loads. The Frank-Starling law and the Anrep effect describe exquisite intrinsic mechanisms the heart has for autoregulating the force of contraction to maintain cardiac output under preload and afterload. Although these mechanisms have been known for more than a century, their cellular and molecular underpinnings are still debated. How does the cardiac myocyte sense a change in preload or afterload? How does the myocyte adjust its response to compensate for such changes? In cardiac myocytes Ca(2+) is a crucial regulator of contractile force and in this review we compare and contrast recent results from different labs that address two important questions...
January 18, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28090307/hemodynamic-response-to-treatment-of-iron-deficiency-anemia-in-pulmonary-arterial-hypertension-longitudinal-insights-from-an-implantable-hemodynamic-monitor
#5
Muddassir Mehmood, Richa Agarwal, Amresh Raina, Priscilla Correa-Jaque, Raymond L Benza
Despite new therapeutic options, pulmonary arterial hypertension (PAH) remains a progressive disease associated with substantial morbidity and mortality. As such, additional strategies for monitoring and adjunctive management of this disease are important. A 59-year-old woman with scleroderma-associated PAH received an implantable hemodynamic monitor (IHM) as part of a research protocol at our institution. Pulmonary artery pressures, heart rate, and cardiac output (sensor-based algorithm) were measured on a daily basis, and parameters of right ventricular (RV) performance and afterload were calculated...
December 2016: Pulmonary Circulation
https://www.readbyqxmd.com/read/28090292/a-new-look-at-bronchopulmonary-dysplasia-postcapillary-pathophysiology-and-cardiac-dysfunction
#6
Arvind Sehgal, Andra Malikiwi, Eldho Paul, Kenneth Tan, Samuel Menahem
Pulmonary hypertension (PH) and right ventricular function are the focus of cardiovascular effects of bronchopulmonary dysplasia (BPD). We assessed cardiac indexes reflecting systemic afterload and pulmonary venous back pressure as pathophysiologic factors. Cardiac parameters were measured by conventional echocardiography in 20 preterm infants with severe BPD and compared with those of 10 preterm infants with no BPD and 20 healthy term infants. In infants with severe BPD, PH was noted in 5 (25%) by tricuspid regurgitation Doppler jet ≥2...
December 2016: Pulmonary Circulation
https://www.readbyqxmd.com/read/28087265/myocardial-relaxation-is-accelerated-by-fast-stretch-not-reduced-afterload
#7
Charles S Chung, Charles W Hoopes, Kenneth S Campbell
Fast relaxation of cross-bridge generated force in the myocardium facilitates efficient diastolic function. Recently published research studying mechanisms that modulate the relaxation rate has focused on molecular factors. Mechanical factors have received less attention since the 1980s when seminal work established the theory that reducing afterload accelerates the relaxation rate. Clinical trials using afterload reducing drugs, partially based on this theory, have thus far failed to improve outcomes for patients with diastolic dysfunction...
January 11, 2017: Journal of Molecular and Cellular Cardiology
https://www.readbyqxmd.com/read/28079557/dobutamine-aggravates-haemodynamic-deterioration-induced-by-pleural-effusion-a-randomised-controlled-porcine-study
#8
Kristian B Wemmelund, Anders H Sørensen, Viktor K Ringgård, Erik Sloth, Peter Juhl-Olsen
BACKGROUND: Pleural effusion is a common finding in critically ill patients and may contribute to circulatory instability and the need for inotropic support. OBJECTIVE: We hypothesised that dobutamine would affect the physiological determinants preload, afterload, contractility and changes of inferior vena cava characteristics during experimental pleural effusion. DESIGN: A randomised, controlled laboratory study. SETTING: Animal laboratory, conducted from March 2013 to May 2013...
January 11, 2017: European Journal of Anaesthesiology
https://www.readbyqxmd.com/read/28077821/ascending-aortic-constriction-promotes-cardiomyocyte-proliferation-in-neonatal-rats
#9
Zhenhua Wang, Sebastian Schmull, Hui Zheng, Jianggui Shan, Rongjiang Zou, Song Xue
Adult heart suffering from increased workload will undergo myocardial hypertrophy, subsequent cardiomyocyte (CM) death, and eventually heart failure. However, the effect of increasing afterload on the neonatal heart remains unknown. We performed ascending aortic constriction (AAC) in neonatal rats 8-12 hours after birth (P0, P indicates postpartum). Seven days after surgery, in vivo heart function was evaluated using cardiac ultrasonography. Haematoxylineosin and Masson staining were used to assess CM diameter and collagen deposition...
January 11, 2017: International Heart Journal
https://www.readbyqxmd.com/read/28072930/left-ventricular-outflow-tract-obstruction-be-prepared
#10
J S Evans, S J Huang, A S McLean, M Nalos
The current trend to treat hypotension in critically ill patients is to place a greater emphasis on inotropic support and less on fluid resuscitation in order to limit the potential harm from fluid overload. This combination may trigger left ventricular outflow tract obstruction (LVOTO) in susceptible patients. Although LVOTO is classically described in patients with hypertrophic cardiomyopathy it has been reported in other conditions including septic shock, apical ballooning syndrome, myocardial infarction, respiratory failure, and post valvular surgery...
January 2017: Anaesthesia and Intensive Care
https://www.readbyqxmd.com/read/28072699/prevention-preferable-to-treatment-3-case-reports-of-patients-experiencing-right-sided-heart-failure-after-ebstein-anomaly-correction
#11
Ming Luo, Jing Lin, Zhen Qin, Lei Du
RATIONALE: Ebstein anomaly is a common congenital heart disease that may induce severe tricuspid regurgitation and dilation of the "atrialized" portion of the right ventricle. Patients who undergo surgery to correct Ebstein anomaly are at high risk of postoperative right-sided heart failure, yet little is known about what pre-, peri-, or postoperative procedures may help reduce this risk. PATIENT CONCERNS: Here, we describe 3 cases of adults with Ebstein anomaly who underwent corrective surgery and in whom right-sided heart failure occurred with severe tricuspid regurgitation detected by transesophageal echocardiography...
January 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28062414/a-novel-complex-i-inhibitor-protects-against-hypertension-induced-left-ventricular-hypertrophy
#12
Nobutoshi Matsumura, Ian M Robertson, Shereen M Hamza, Carrie-Lynn M Soltys, Miranda M Sung, Grant Masson, Donna L Beker, Jason R B Dyck
Since left ventricular hypertrophy (LVH) increases the susceptibility for the development of other cardiac conditions, pharmacotherapy that mitigates pathological cardiac remodeling may prove to be beneficial in patients with LVH. Previous work has shown that the activation of the energy-sensing kinase, AMP-activated protein kinase (AMPK), can inhibit some of the molecular mechanisms that are involved in LVH. Of interest, metformin activates AMPK through its inhibition of mitochondrial complex 1 in the electron transport chain, and can prevent LVH induced by pressure overload...
January 6, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28057053/a-pig-model-of-acute-right-ventricular-afterload-increase-by-hypoxic-pulmonary-vasoconstriction
#13
Kathrine Knai, Nils Kristian Skjaervold
BACKGROUND: The aim of this study was to construct a non-invasive model for acute right ventricular afterload increase by hypoxic pulmonary vasoconstriction. Intact animal models are vital to improving our understanding of the pathophysiology of acute right ventricular failure. Acute right ventricular failure is caused by increased afterload of the right ventricle by chronic or acute pulmonary hypertension combined with regionally or globally reduced right ventricular contractile capacity...
January 3, 2017: BMC Research Notes
https://www.readbyqxmd.com/read/28048820/su-f-t-11-scintillator-based-quality-assurance-device-for-hdr-brachytherapy
#14
G Jozsef
PURPOSE: To build a test device for HDR afterloaders capable of checking source positions, times at positions and estimate the activity of the source. METHODS: A catheter is taped on a plastic scintillation sheet. When a source travels through the catheter, the scintillator sheet lights up around the source. The sheet is monitored with a video camera, and records the movement of the light spot. The center of the spot on each image on the video provides the source location, and the time stamps of the images can provide the dwell time the source spend in each location...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048740/su-f-t-07-dosimetric-impact-of-the-dwell-position-inaccuracy-in-hdr-ring-and-tandem-treatments-with-varisourceix-afterloader
#15
I Veltchev, R Price, P Anderson, C Ma
PURPOSE: The dwell positions in the VariSourceIX HDR ring applicator are known to be somewhat inaccurate with observed deviations from the planned position of up to 5mm. The details of how to correct this issue are suggested by the vendor and the dosimetric impact on volumetric HDR plans varies from patient to patient. In this study we present our experience with correcting this issue, and discuss the impact on plan quality if the planned dwell positions were left unchanged. METHODS: A 60 degree ring was characterized using gafchromic film with the applicator in treatment orientation...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048639/tu-h-209-02-quality-assurance-and-qmp-for-brachytherapy-treatment-delivery-and-treatment-planning-system
#16
M Chilukuri
Learnings Objectives: 1. Although brachytherapy is the oldest form of radiation therapy, the rapid advancement of the methods of dose calculation, treatment planning and treatment delivery pushes us to keep updating our knowledge and experience to new procedures all the time. Our purpose is to present the newest applicators used in Accelerated Partial Breast Irradiation (APBI) and the techniques of using them for a maximum effective treatment. Our objective will be to get the user familiar with the Savi, Contura and ML Mammosite from the detailed description and measurements to cavity eval and choice or size, to acceptance tests and use of each...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047974/tu-h-209-03-planning-and-treatment-delivery-for-apbi-using-savi-contura-and-ml-mammosite
#17
S Pella
Learnings Objectives: 1. Although brachytherapy is the oldest form of radiation therapy, the rapid advancement of the methods of dose calculation, treatment planning and treatment delivery pushes us to keep updating our knowledge and experience to new procedures all the time. Our purpose is to present the newest applicators used in Accelerated Partial Breast Irradiation (APBI) and the techniques of using them for a maximum effective treatment. Our objective will be to get the user familiar with the Savi, Contura and ML Mammosite from the detailed description and measurements to cavity eval and choice or size, to acceptance tests and use of each...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047720/su-f-t-633-cyberknife-boost-versus-conventional-tandem-and-ovoid-treatment-for-cervical-cancer
#18
J Santoro, M Witten, J Haas
PURPOSE: Brachytherapy has been the standard of care for cervical cancer for 100 years. The treatment can be administered using an HDR (high dose rate) remote afterloader with a (192) Ir source in an outpatient setting, a PDR afterloader with a (192) Ir source, or with LDR manually loaded or a remote afterloader utilizing (192) Ir or (137) Cs sources in an inpatient setting. The procedure involves the placement of a tandem and ovoid, tandem and ring, or tandem and cylinder applicator in an operating room setting with the patient under general anesthesia...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047715/we-de-201-08-multi-source-rotating-shield-brachytherapy-apparatus-for-prostate-cancer
#19
H Dadkhah, X Wu, Y Kim, R Flynn
PURPOSE: To introduce a novel multi-source rotating shield brachytherapy (RSBT) apparatus for the precise simultaneous angular and linear positioning of all partially-shielded 153Gd radiation sources in interstitial needles for treating prostate cancer. The mechanism is designed to lower the detrimental dose to healthy tissues, the urethra in particular, relative to conventional high-dose-rate brachytherapy (HDR-BT) techniques. METHODS: Following needle implantation, the delivery system is docked to the patient template...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047569/su-f-t-34-transition-form-ct-based-to-ultrasound-based-hdr-treatment-planning-for-prostate-cancer
#20
I Veltchev, R Price, E Horwitz, C Ma
PURPOSE: We discuss our experience with the transition from CT-based to ultrasound-based HDR treatment planning for prostate cancer in a high-volume clinical setting. The details of switching from one afterloader vendor to another are also discussed. The four main stages of prostate HDR planning (image acquisition, target delineation, needle reconstruction, and plan optimization) are significantly modified when ultrasound imaging is used. METHODS: We employ a time-efficient needle reconstruction procedure that provides the necessary level of accuracy to rival the traditional CT-based method...
June 2016: Medical Physics
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